Midland of Buenos Aires 2-8-2 Locomotives in Argentina

Class Details by Steve Llanso of Sweat House Media

Class unknown (Locobase 20181)

Data from "A Novel Locomotive for the Argentine", Locomotive Magazine, Volume XIX [19] (15 January 1913), p. 20.

The novelty found in this locomotive's design was in its frame. The front part, which extended from the front buffer beam to behind the last coupled axle, was formed by the set of frame plates, "stiffly braced together in the usual manner." From there to the tender coupler pocket, a single heavy girder extended along the locomotive's centerline, its profile dipping to take the firebox, then rising to support the footplate.

But there was more innovation in store. Between the two tubeplates at each end, the builder inserted a secondary tubeplate about 3/4s of the way to the front tubesheet that created a separate compartment over the front quarter. The idea was to inject the feed water into the lower section, where "the least useful portion of the heating surface of the tubes is utilised in raising the feed water to boiler temperature." Moreover, "all impurities and sediment" would be "readily removed through a mudhole." Shields prevented cool water from rising and another prevented water from cooling the steam in the dry pipe.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID20181
RailroadMidland of Buenos Aires
Number in Class
Road Numbers
Number Built
Valve GearHeusinger
Locomotive Length and Weight
Driver Wheelbase (ft / m)11.98 / 3.65
Engine Wheelbase (ft / m)29.20 / 8.90
Ratio of driving wheelbase to overall engine wheelbase 0.41
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)23,521 / 10,669
Weight on Drivers (lbs / kg)91,492 / 41,500
Engine Weight (lbs / kg)125,663 / 57,000
Tender Loaded Weight (lbs / kg)77,162 / 35,000
Total Engine and Tender Weight (lbs / kg)202,825 / 92,000
Tender Water Capacity (gals / ML)3432 / 13
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)38 / 19
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)41.30 / 1050
Boiler Pressure (psi / kPa)184.20 / 12.70
High Pressure Cylinders (dia x stroke) (in / mm)17.32" x 21.26" / 440x540
Tractive Effort (lbs / kg)24,178 / 10966.97
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.78
Heating Ability
Tubes (number - dia) (in / mm)179 - 2.165" / 55
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)96.34 / 8.95
Grate Area (sq ft / m2)27.99 / 2.60
Evaporative Heating Surface (sq ft / m2)1722 / 160
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1722 / 160
Evaporative Heating Surface/Cylinder Volume297.03
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5156
Same as above plus superheater percentage5156
Same as above but substitute firebox area for grate area17,746
Power L14820
Power MT464.58

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